Iron Cross for a Lie. Misdirecting Hitler Forces using Turned German Spies

Of the 115 German agents captured or received by British intelligence during World War II, not one remained loyal to the Reich. Fifteen were executed. The rest were turned - and through them, the British Security Service MI5 conducted the most precise manipulation of an enemy's military mind in modern history. The policy had a deceptively simple architecture: allow the turned agents to keep transmitting to their Abwehr handlers, feed them a curated mixture of authentic detail and calculated fiction, and use Ultra decrypts from Bletchley Park to verify in real time what Berlin was choosing to believe. At the centre of this network stood figures whose improbability bordered on fiction.
Agent Garbo - Juan Pujol García, a Spanish anti-fascist who had never set foot in Britain when he began filing detailed intelligence reports to German handlers from a Lisbon hotel room, consulting library books for local colour - had by 1944 convinced the Abwehr he commanded a network of 27 agents across the United Kingdom. None of them existed. His reports were so trusted that when the Normandy landings began on 6 June 1944, his message - transmitted at 0300, declaring the invasion a feint and the real strike destined for Pas-de-Calais - persuaded Hitler to hold two Panzer divisions in reserve for seven critical weeks, while the Allied beachhead solidified unopposed.
On 29 July 1944, Adolf Hitler personally approved the award of the Iron Cross to Juan Pujol García - for lying to him.